You're right about the weight gain. I was on Olanzapine for a month and put on a stone. I stopped taking it because due to another unpleasant side effect and the weight I'd put on just dropped off. When I was taking Olanzapine I always felt hungry, craved sweets and cakes and I never felt full after a meal. I've just started taking them again yesterday so fingers crossed I can control the cravings etc better this time.